Anupubba

Setthi of Sāvatthi. He was so called
because he engaged himself in a series of good works, each being of greater
merit than the last, with the object of freeing himself from suffering. In the
end he entered the Order, but finding the rules too numerous and irksome, he
wished to return to the lay-life. His colleagues took him to the Buddha, who
asked him to observe one rule only - guarding his mind; he agreed and became a
Stream-enterer. DhA.i.297-300.